Electrode.



'c. w. DAKE.

. ELECTRODE. APPLICATION FILED JAN|31| l9l4- WITNESSES: 1 INVENTOR gan 2% Pz%e,

TED s'r AtrEs PATE- on ron.

CHARLES W. DAKE, OF CHICAGO, ILLINOIS, ASSIGNOR TO PYLE-NATIONAL ELECTRIC HEADLIGHT COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION OF NEW JERSEY.

ELECTRODE.

Specification of Letters Tatent.

Patented Jan. 16, 191?.

Application filed January 31, 1914. Serial N 0. 815,600.

To all whom it may concern:

Be it known that I, CHARLES W. DAKE, a citizen of the United. States, residing at Chicago, in the county of Cook and State of lllinois liave'invented a certain new and useful Improvement in Electrodes, of which the following is a specification.

When it is necessary in arc lighting to kep the electric arc fixed in position as, for instance, in connection with locomotive headlights Where it is essential that the arc remain at the focal point, experience shows that it is desirable to use for one of the electrodes, preferably the negative, a copper or other metallic member whose character-f istic is that it is but slowly consumed by the arc. Since only a'slight displacement of the arc is allowable, it is, therefore, necessary to provide means for warning the operator when the negative electrode has been toov which notifies the operator by changing the color of the arc and subsequently by extinguishing the are so that he not only knows what is needed but absolutely must comply with the requirement. I

My invention relates, therefore, to improvements in electrodes for are lamps and the like and is illustrated in one form in the accompanying drawing, wherein- Figure 1 is a side elevation in part section of the two electrodes showing diagrammatically the wiring connections; Fig. 2 is a side elevation of the metallic electrode; Fig. 3 is a bottom plan view; Fig. 4, a section similar to the section shown in Fig. 1, showing the electrode partly consumed; and Fig. 5, a similar section showing the electrode burnt out.

Like numerals refer to like out the several figures.

1 is a negative electrode for an arc lamp made of copper or other suitable materia the only requirement being thatthe metal or material of which it is made be a conductor and one which is but slowly destroyed by the operation of thearc. 2 is a positive carbon rod or encil electrode.

3 is a conductor leading from the positive parts throughelectrode 2 to the generator 4, and 5is a conductor leading from the generator 4 to the negative electrode 1 The negative electrode 1 is made of a cylindrical shank Cterminating in an expanded conical head A which head has a base B upon which it is adapted to rest to fix it in position. The shank C together with the head A is cored or drilled asindicated: The bottom of the hole which extends almost to the apex of the cone contains a conducting plug D of some material preferably of metal such as lithium or strontium which when acted on by the open arc will change the color of the arc.

E is an'insulating plug of asbestos or other suitable material which, when the arc has consumed the plug D, will extinguish the arc. v

F is a metallic plug of any .suitable con ducting metal to close the hole and hold the plugs D and E in position.

The use and operation of my invention are as follows: The lamp aside from the two electrodes I have not shown as any suitable electrode controlling means of any kind whatever might be used. The metallic negative electrode is, of course, adapted to be fixed in position resting upon the base of the cone. It is this electrode which is used up and then thrown away. The distance from the top of this electrode to the surface of the insulating plug is the maximum distance through which the arc may be displaced without disastrous consequences. As the light operates, the carbon or positive electrode will be fed down, being gradually consumed. The metallic or negative electrode will be consumed but not so rapidly. This consuming of the negative electrode will continue until a crater is opened up somewhat similar to that shown diagrammatically in Fig. 4, exposing the upper conducting plug. The arc will be formed then through and across this plug and the color will be changed radically, preferably to a bright red, although other materials producing different colors might be used. This continues until the plug is consumed down to the insulating plug, and the presence of this insulatin plug, of course, interrupting the current Wlll break the arc and the light will go out. The operator having previously seen the colored light will know when the light goes out'what is the matter and will instantly remove, the burnt out negative electrode and replace it by a new one, whereupon the lamp can again be used.- I have suggested the use of such metals as lithium or strontium because they do give a bright red light which is unmlstakably noticeable and most likely to warn the operator, although other materials might be used. The same is true of the asbestos .plug. This is a good insulator, and it is not hurt by the heat of the arc, butfother materials might be used without departing, of course, from the spirit of my invention or w thout chang- 'ing materially the. result obtained.

I claim:

. IL-In an arc lamp electrode, means for exposed to the action of the are changes its ing made up exposed to the action subsequently color and a lower'insulation plug which extinguishes the arc.

3. An arc lamp electrode comprising a metallic shell, a plug contained therein and embedded in the. body thereof, said plug made up of a material which when exposedto the action'of the are changes its color, and an insulating plug beneath supporting said color plug.

4:. An arc lamp electrode comprising a conducting body, a plug contained therein embedded in the body thereof and removed from the normal arcing point, saidplug beof amaterlal such that when of the are it changes the color of the arc, an insulating plug adapted to interrupt the current and extinguish the are when the color plug has been burned away.

In testimony whereof, I aflix my slgnature in the presence of two witnesses this 26th day of January, 1914. v

v CHARLES -W. DAKE. Witnesses:

GENEVA IRTH,

LAUREL M. Dorm/ms, 

